Sentinel node biopsy: ALARA and other considerations.

For a majority of solid tumors, the most powerful and predictive prognostic factor is the status of the regional lymph nodes. Sentinel lymph node sampling continues to gain in popularity as patients and their physicians seek to avoid the potential morbidity associated with standard axillary node dissection. Lymphoscintigraphy, one of the recently explored techniques of lymphatic mapping, involves pre-operative intradermal or subcutaneous administration of a radiopharmaceutical. While this approach is gaining widely spread acceptance, there is still a lack of consensus on which radiopharmaceutical agent has the most ideal properties. By far, the most commonly used agents are 99mTc labeled colloids, but other agents are also used clinically and are under investigation or development worldwide. A number of other clinical, technical, dosimetric, and logistical considerations regarding this procedure remain. They include questions such as who should be performing the procedure, what precautions to take during surgery, how to better isolate "hot" nodes and thus improve the efficacy of determining metastases to the draining lymph node, what precautions to take when handling surgical specimens, etc. There is clearly a need to review as low as reasonably achievable considerations and other issues that arise as this technique evolves and finds its role in the evaluation of various types of cancers. This paper, based on our own experiences and those of others, fills this gap.